1. Multiple Sclerosis Unit, Institute of Biomedical Investigation, University Hospital of Bellvitge, Faculty of Medicine, Campus Bellvitge, University of Barcelona, Spain,
2. Multiple Sclerosis Unit, Institute of Biomedical Investigation, University Hospital of Bellvitge, Faculty of Medicine, Campus Bellvitge, University of Barcelona, Spain
3. Department of Neurology, Hospital de San Lorenzo, Viladecans, Barcelona, Spain
4. Department of Neurology, Hospital de Figueres, Girona, Spain